Lord Stephen R, Dayhew Julia, Howland Amelia
Prince of Wales Medical Research Institute, Randwick, University of New South Wales, Australia.
J Am Geriatr Soc. 2002 Nov;50(11):1760-6. doi: 10.1046/j.1532-5415.2002.50502.x.
To determine the extent to which multifocal glasses impair contrast sensitivity and depth perception at critical distances required for detecting hazards in the environment and whether multifocal glasses use increases the risk of falls in older people.
One-year prospective cohort study.
Falls Laboratory, Prince of Wales Medical Research Institute.
One hundred fifty-six community-dwelling people aged 63-90.
Contrast sensitivity, depth perception, accidental falls.
Eighty-seven subjects (55.8%) were regular wearers of multifocal (bifocal, trifocal, or progressive lens) glasses. These subjects performed significantly worse in the distant depth perception and distant edge-contrast sensitivity tests in conditions that forced them to view test stimuli through the lower segments of their glasses. Multifocal glasses wearers were more than twice as likely to fall in the follow-up period than nonmultifocal glasses wearers (odds ratio (OR) = 2.29, 95% confidence interval (CI) = 1.06-4.92), when adjusting for age, poor vision, reduced lower limb sensation and strength, slow reaction time, and increased postural sway. Multifocal glasses wearers were also more likely to fall because of a trip (OR = 2.79, 95% CI = 1.08-7.22), when outside their homes (OR = 2.55, 95% CI = 1.14-5.70), and when walking up or down stairs (P <.01). The population attributable risks of regular multifocal glasses use were 35.2% for any falls, 40.9% for falls due to a trip, and 40.9% for falls outside the home.
The study findings indicate that multifocal glasses impair depth perception and edge-contrast sensitivity at critical distances for detecting obstacles in the environment. Older people may benefit from wearing nonmultifocal glasses when negotiating stairs and in unfamiliar settings outside the home.
确定多焦点眼镜在检测环境中的危险所需的关键距离上损害对比敏感度和深度感知的程度，以及佩戴多焦点眼镜是否会增加老年人跌倒的风险。
为期一年的前瞻性队列研究。
威尔士王子医学研究所跌倒实验室。
156名年龄在63 - 90岁的社区居民。
对比敏感度、深度感知、意外跌倒。
87名受试者（55.8%）经常佩戴多焦点（双焦点、三焦点或渐进多焦点镜片）眼镜。在迫使他们通过眼镜下部观看测试刺激的条件下，这些受试者在远距离深度感知和远距离边缘对比敏感度测试中的表现明显更差。在调整年龄、视力差、下肢感觉和力量下降、反应时间慢以及姿势摆动增加等因素后，佩戴多焦点眼镜的人在随访期间跌倒的可能性是非佩戴多焦点眼镜者的两倍多（优势比（OR）= 2.29，95%置信区间（CI）= 1.06 - 4.92）。佩戴多焦点眼镜的人也更有可能因绊倒而跌倒（OR = 2.79，95% CI = 1.08 - 7.22），在户外时（OR = 2.55，95% CI = 1.14 - 5.70），以及上下楼梯时（P <.01）。经常使用多焦点眼镜导致跌倒的人群归因风险分别为：任何跌倒为35.2%，绊倒导致的跌倒为40.9%，户外跌倒为40.9%。
研究结果表明，多焦点眼镜在检测环境中的障碍物的关键距离上会损害深度感知和边缘对比敏感度。老年人在上下楼梯和户外不熟悉的环境中佩戴非多焦点眼镜可能会受益。
